CVE-2026-57403
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedImproper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Milan Petrovic GD Security Headers gd-security-headers allows Reflected XSS.This issue affects GD Security Headers: from n/a through <= 1.8.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceA reflected cross-site scripting (XSS) vulnerability exists in the GD Security Headers plugin (versions through 1.8) by Milan Petrovic. The plugin fails to properly neutralize user-supplied input during web page generation, allowing attackers to inject malicious scripts that execute in the context of the victim's browser.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Verify GD Security Headers plugin is installedCheck your WordPress plugin directory or admin panel for the presence of the GD Security Headers plugin by Milan PetrovicAffected if The plugin is installed and active in the WordPress environment
-
Determine the installed plugin versionAccess the WordPress admin panel, navigate to Plugins > Installed Plugins, and locate the GD Security Headers plugin to view its version number. Alternatively, inspect the plugin's main PHP file header for the Version fieldAffected if The installed version is 1.8 or any version lower than 1.8
-
Confirm the plugin handles user-supplied inputReview the plugin settings and functionality to identify any features that accept and process user-controlled data (such as query parameters, form inputs, or admin-supplied values) and reflect them into web page outputAffected if The plugin is configured to process and display user-supplied input in any web-accessible context (admin dashboard pages, front-end output, or HTTP headers generated from user data)
-
Inspect page source for unencoded reflected dataUse browser developer tools or view source to examine the HTML output of any page where the plugin processes user input. Look for raw, unescaped characters from URL parameters or admin inputs appearing in the rendered pageAffected if User-supplied data appears in the page source without proper HTML entity encoding (e.g., unescaped <, >, or quote characters)
You are affected if the GD Security Headers plugin (versions 1.8 and below) is active and any of its features reflect user-supplied input into web pages without proper sanitization.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpdate GD Security Headers to the latest version once available, which should include proper input validation/sanitization. Alternatively, implement output encoding at the application layer for all user-controlled data before rendering.
- Consultation2.0 h
- Implementation1.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,936.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-57403 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-57403 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data